tim/prune/load/xml/GpxHandler.java

   1 package tim.prune.load.xml;
   2
   3 import java.util.ArrayList;
   4
   5 import org.xml.sax.Attributes;
   6 import org.xml.sax.SAXException;
   7
   8 import tim.prune.data.Field;
   9 import tim.prune.load.TrackNameList;
  10
  11
  12 /**
  13  * Class for handling specifics of parsing Gpx files
  14  */
  15 public class GpxHandler extends XmlHandler
  16 {
  17         private boolean _insidePoint = false;
  18         private boolean _insideWaypoint = false;
  19         private boolean _startSegment = true;
  20         private boolean _isTrackPoint = false;
  21         private int _trackNum = -1;
  22         private GpxTag _name = new GpxTag(), _trackName = new GpxTag();
  23         private String _latitude = null, _longitude = null;
  24         private GpxTag _elevation = new GpxTag(), _time = new GpxTag();
  25         private GpxTag _type = new GpxTag(), _description = new GpxTag();
  26         private GpxTag _link = new GpxTag();
  27         private GpxTag _currentTag = null;
  28         private ArrayList<String[]> _pointList = new ArrayList<String[]>();
  29         private ArrayList<String> _linkList = new ArrayList<String>();
  30         private TrackNameList _trackNameList = new TrackNameList();
  31
  32
  33         /**
  34          * Receive the start of a tag
  35          * @see org.xml.sax.ContentHandler#startElement(java.lang.String, java.lang.String, java.lang.String, org.xml.sax.Attributes)
  36          */
  37         public void startElement(String uri, String localName, String qName,
  38                 Attributes attributes) throws SAXException
  39         {
  40                 // Read the parameters for waypoints and track points
  41                 String tag = qName.toLowerCase();
  42                 if (tag.equals("wpt") || tag.equals("trkpt") || tag.equals("rtept"))
  43                 {
  44                         _insidePoint = true;
  45                         _insideWaypoint = tag.equals("wpt");
  46                         _isTrackPoint = tag.equals("trkpt");
  47                         final int numAttributes = attributes.getLength();
  48                         for (int i=0; i<numAttributes; i++)
  49                         {
  50                                 String att = attributes.getQName(i).toLowerCase();
  51                                 if (att.equals("lat")) {_latitude = attributes.getValue(i);}
  52                                 else if (att.equals("lon")) {_longitude = attributes.getValue(i);}
  53                         }
  54                         _elevation.setValue(null);
  55                         _name.setValue(null);
  56                         _time.setValue(null);
  57                         _type.setValue(null);
  58                         _link.setValue(null);
  59                         _description.setValue(null);
  60                 }
  61                 else if (tag.equals("ele")) {
  62                         _currentTag = _elevation;
  63                 }
  64                 else if (tag.equals("name")) {
  65                         _currentTag = (_insidePoint?_name:_trackName);
  66                 }
  67                 else if (tag.equals("time")) {
  68                         _currentTag = _time;
  69                 }
  70                 else if (tag.equals("type")) {
  71                         _currentTag = _type;
  72                 }
  73                 else if (tag.equals("description")) {
  74                         _currentTag = _description;
  75                 }
  76                 else if (tag.equals("link")) {
  77                         _link.setValue(attributes.getValue("href"));
  78                 }
  79                 else if (tag.equals("trkseg")) {
  80                         _startSegment = true;
  81                 }
  82                 else if (tag.equals("trk"))
  83                 {
  84                         _trackNum++;
  85                         _trackName.setValue(null);
  86                 }
  87                 super.startElement(uri, localName, qName, attributes);
  88         }
  89
  90
  91         /**
  92          * Process end tag
  93          * @see org.xml.sax.ContentHandler#endElement(java.lang.String, java.lang.String, java.lang.String)
  94          */
  95         public void endElement(String uri, String localName, String qName)
  96                 throws SAXException
  97         {
  98                 String tag = qName.toLowerCase();
  99                 if (tag.equals("wpt") || tag.equals("trkpt") || tag.equals("rtept"))
 100                 {
 101                         processPoint();
 102                         _insidePoint = false;
 103                 }
 104                 else {
 105                         _currentTag = null;
 106                 }
 107                 super.endElement(uri, localName, qName);
 108         }
 109
 110
 111         /**
 112          * Process character text (inside tags or between them)
 113          * @see org.xml.sax.ContentHandler#characters(char[], int, int)
 114          */
 115         public void characters(char[] ch, int start, int length)
 116                 throws SAXException
 117         {
 118                 String value = new String(ch, start, length);
 119                 if (_currentTag != null) {
 120                         _currentTag.setValue(checkCharacters(_currentTag.getValue(), value));
 121                 }
 122                 super.characters(ch, start, length);
 123         }
 124
 125
 126         /**
 127          * Check to concatenate partially-received values, if necessary
 128          * @param inVariable variable containing characters received until now
 129          * @param inValue new value received
 130          * @return concatenation
 131          */
 132         private static String checkCharacters(String inVariable, String inValue)
 133         {
 134                 if (inVariable == null) {return inValue;}
 135                 return inVariable + inValue;
 136         }
 137
 138
 139         /**
 140          * Process a point, either a waypoint or track point
 141          */
 142         private void processPoint()
 143         {
 144                 // Put the values into a String array matching the order in getFieldArray()
 145                 String[] values = new String[8];
 146                 values[0] = _latitude;
 147                 values[1] = _longitude;
 148                 values[2] = _elevation.getValue();
 149                 if (_insideWaypoint) {values[3] = _name.getValue();}
 150                 values[4] = _time.getValue();
 151                 if (_startSegment && !_insideWaypoint)
 152                 {
 153                         values[5] = "1";
 154                         _startSegment = false;
 155                 }
 156                 values[6] = _type.getValue();
 157                 values[7] = _description.getValue();
 158                 _pointList.add(values);
 159                 _trackNameList.addPoint(_trackNum, _trackName.getValue(), _isTrackPoint);
 160                 _linkList.add(_link.getValue());
 161         }
 162
 163
 164         /**
 165          * @see tim.prune.load.xml.XmlHandler#getFieldArray()
 166          */
 167         public Field[] getFieldArray()
 168         {
 169                 final Field[] fields = {Field.LATITUDE, Field.LONGITUDE, Field.ALTITUDE,
 170                         Field.WAYPT_NAME, Field.TIMESTAMP, Field.NEW_SEGMENT,
 171                         Field.WAYPT_TYPE, Field.DESCRIPTION};
 172                 return fields;
 173         }
 174
 175
 176         /**
 177          * Return the parsed information as a 2d array
 178          * @see tim.prune.load.xml.XmlHandler#getDataArray()
 179          */
 180         public String[][] getDataArray()
 181         {
 182                 int numPoints = _pointList.size();
 183                 // construct data array
 184                 String[][] result = new String[numPoints][];
 185                 for (int i=0; i<numPoints; i++)
 186                 {
 187                         result[i] = _pointList.get(i);
 188                 }
 189                 return result;
 190         }
 191
 192         /**
 193          * @return array of links, or null if none
 194          */
 195         public String[] getLinkArray()
 196         {
 197                 int numPoints = _linkList.size();
 198                 boolean hasLink = false;
 199                 String[] result = new String[numPoints];
 200                 for (int i=0; i<numPoints; i++)
 201                 {
 202                         result[i] = _linkList.get(i);
 203                         if (result[i] != null) {hasLink = true;}
 204                 }
 205                 if (!hasLink) {result = null;}
 206                 return result;
 207         }
 208
 209         /**
 210          * @return track name list
 211          */
 212         public TrackNameList getTrackNameList() {
 213                 return _trackNameList;
 214         }
 215 }